1. Field of the Invention
The present invention relates to a twin clutch type speed change control system suitable for use in a vehicle such as a motorcycle.
2. Background of the Invention
Conventionally, there has been a twin clutch type speed change control system including a transmission mechanism having a plurality of gear trains for odd-ordinal gear positions and even-ordinal gear positions, and a pair of clutches linked respectively to both of the odd-ordinal and even-ordinal gear position gear trains. The transmission mechanism is capable of power transmission by selectively using one of the gear trains. One of the clutches is engaged and the other of the clutches is disengaged during a normal operation with a fixed gear position so as to transmit power by use of one of the gear trains linked to the engaged clutch and to develop a condition where power transmission can be performed by use of a preliminarily selected one of the gear trains linked to the disengaged clutch. Starting from this condition, the engaged clutch is disengaged and the disengaged clutch is engaged, whereby changeover between the odd-ordinal gear position and the even-ordinal gear position is performed (refer to, for example, Japanese Patent Laid-Open No. 2007-177904).
The transmission mechanism can perform power transmission by selectively using one of the gear trains through a process in which a slide member rotated as one body with a support shaft in each of the gear trains is mutually non-rotatably engaged with a free gear mutually rotatable in relation to the support shaft.
During the above-mentioned normal operation, in the disengaged clutch, a component part on the drive source side is rotated idly relative to a component part on the gear train side. In this instance, the component part on the gear train side of the clutch and a gear train contiguous to the component part are at stoppage of rotation, and, at the time of changeover of the gear position, a comparatively high rotational acceleration acts on the preliminarily selected gear train. Therefore, between the free gear and the slide member corresponding to this gear train, a collision sound based on a mechanical play between these components may be generated, and an improvement of this point is being demanded.